Health & Nutrition
Heart Rate Zones
Updated 2026-01-09
Definition
Percentage ranges of your maximum heart rate, each producing a distinct training effect. Max HR is commonly estimated as 220 minus your age, though the Tanaka formula (208 − 0.7 × age) is more accurate for adults. Zone 2 (60-70%) builds aerobic base and mitochondrial density. Zone 3 (70-80%) improves lactate threshold. Zone 4 (80-90%) trains VO2 max adaptations. Zone 5 (90-100%) develops anaerobic capacity. Endurance athletes spend 80% of training time in Zone 2, a pattern known as polarized training.
Primary source: American Heart Association target HR
Related Calculators
- Heart Rate Zone Calculator - Calculate your target heart rate training zones based on maximum heart rate.
- VO2 Max Calculator - Estimate your VO2 max (maximal oxygen uptake), a key indicator of cardiovascular fitness.
- Running Pace Calculator - Calculate your running pace per mile or kilometer from distance and time.